Treatment of hydrocarbons



Patented June 27, 1939 i 1} UNITED STATES 2,163,858 ram'mnnrornrnaoceaaons Robert D. Snow, Bartlesville, kla., assignor to PhilipsPetroleum Company, a corporation of Delaware I No Drawing... ApplicationDecember 20, 1931,

' Serial No.180,9 12

I 12 Claims.

This invention relates to the treatment of hydrocarbon mixtures and moreparticularly to their treatment by selective solution in a liquidsolvent.

This is a continuation-in-part of my copending application, SerialNumber 708,523, filed January 26, 1934 which is now U. S. Patent2,102,654, wherein it is disclosed that new and useful substances may beprepared by treating or reacting sulphur dioxide-olefin complexes withaqueous or alcoholic alkali or alkaline earth hydroxide solutions,ammonium hydroxide, liquid ammonia, and amines or other substitutedammonia compounds. The substances formed comprise acidic organicdecomposition products and/or theirsalts, neutral oils or oily productsand other organic decomposition products.

These neutral oils or oily products are formed when sulphur dioxideolefin complexes or resins are reacted with strong alkalis such assodium, lithium and potassium hydroxides and the like. Solutions ofsubstituted ammonium bases such as (CH3)4NOH and the like may also beused. The exact nature or chemical formula of these oils is not known tome at this time. However, their method of preparation is known, asoutlined in my aforementioned application Serial Number not at one endof the double bond or olefin link-' age. As an example, resinsv formedfrom sulfur dioxide and 2-butene, 2-pentene, 2-hexene and the like, canbe reacted with an approximately 25-45 per cent aqueous solution of astrong alkali, and a neutral oil can be extracted from the reactionproducts. Such oil will be formed in yields up to 40 per cent or more ofthe original S02- olefin resin; These oils are neutral as to acid orbasic reaction and for the sake of simplicity such-oils will be referredto herein and in the,

claims appended hereto as SOz-olefih-resin oils.,

It is an object of this invention to separate hydrocarbons of one typeor class from hydrocarbons of another type or class.

form a solvent extraction process wherein hydrocarbon mixturescontaining two or more types or classes of hydrocarbons are separatedinto at least two parts, one of which contains less of at least one typethan either the original mixture or one of the other parts.

Another object of this invention is to subject a lubricating oil totreatment whereby its viscosity-temperature characteristics areimproved.

Further objects and advantages will be apparent to those skilled in theart as the following discussion and disclosure proceeds.

I have found that these SOz-olefln-resin oils are somewhat soluble invarious hydrocarbons and types or groups of hydrocarbons, and also thatvarious hydrocarbons and types or groups of hydrocarbons are even moresoluble in these SOz-olefln-resin oils. These types or. groups ofhydrocarbons range from saturated hydrocarbons, or parafllns, throughthe various hydrogendeficient hydrocarbons such as oleflns andnaphthenes to the most hydrogen deficient, or aromatic, hydrocarbons. Ihave found that in either case the degree of solubility variesconsiderably with the temperature, and I have further found that thedegree of solubility varies widely with the type or group ofhydrocarbons being considered. Although paraflln hydrocarbons arerelatively insoluble in the SOz-olefln-resin oil, the highly hydrogendeficient aromatic'hydrocarbons are completely miscible with thismaterial over a large temperature range, while the intermediatelyhydrogendeflcie'nt naphthene and olefin hydrocarbons have intermediatesolubility properties. This is illustrated in Table I, in which theresults obtained by intimately mixing equal volumes of hydrocarbon andSOz-butene-Z resin oil and allowing the liquid phases to separate aretabulated as the volumes of the two phases in per cent of the totalliquid volume.

I have been able to use my invention relative to these SOz-olefin-resinoils in a number of ways. It is well known that natural petroleums, andportions thereof which have been separated by distillation of one sortand another, are composed of various amounts of various types or groupsof hydrocarbons. The kinds and amounts of these hydrocarbons varyconsiderably both with the location where the petroleum is found andwith the boiling range of any particular fraction.

, When these petroleums, or fractions thereof are subjected either tothermal or catalytic decomposition, other groups of hydrocarbons areformed. Hydrocarbons of various groups are also present in products fromcoke ovens and the like.

The presence of various hydrocarbon groups in many petroleum fractionsor mixtures of hydrocarbons is often undesirable, as one group or typemay be less suited to perform a given function than some other group.Lubricating oils, typified by viscous petroleum fractions or residues,contain many types of hydrocarbonsparaflins, naphthenes and aromaticsandthe removal of the more hydrogen deficient types by selective solventextraction leads to improved characteristics, notably decreased sludgeformation during use as an engine lubricant and also improvedviscosity-temperature characteristics. As will be subsequently shown inmore detail, I have been able to improve lubricating oils by such asolvent extraction using SOz-olefin-resin oils as selective solvents.

Hydrocarbon mixtures in the motor fuel boiling range also containvarious proportions of different groups of hydrocarbons. In thepreparation of special fuels from such hydrocarbon mixtures, or even inthe preparation of ordinary motor fuels, it is often desirable toseparate or concentrate one or more of these groups of hydrocarbons. Ingeneral the more hydrogen deficient hydrocarbons have less detonatingtendency than more saturated hydrocarbons, but the detonatingcharacteristics of the members of any particular group also vary widelyamong themselves. By practicing my invention I am able to produce morevaluable motor fuels in a number of ways. Essentially parafiinic motorfuels with undesirable detonating characteristics may be subjected toany of a number of cracking or reforming processes, wherebyhydrogen-deficient hydrocarbons of more desirable characteristics inthis respect are produced. My invention is then used to concentratethese reformed products, so that the unaffected hydrocarbons may betreated further. Again, with motor fuels containing originallyappreciable quantities of aromatic hydrocarbons, or other non-parafiinichydrocarbons of good antidetonating qualities, I am able to concentratethese and subject the remaining hydrocarbons to any desirable reformingtreatment. 0n the other hand, alkylation processes produce highlybranched paraffins which have excellent antidetonating characteristicswithout attendant tendencies to deleterious gum formation and the like.Hydrogen-deficient hydrocarbons such as olefins, concomitantly produced,may be nondestructively hydrogenated to paraflins, but in many suchcases the parafiins so produced are inferior to the other parafiinsoriginally present. In such a case a concentration of the paraflins byremoval of the hydrogen-deficient hydrocarbons is the most beneficialtreatment, and is easily carried out by means of this invention. In thismanner a premium paramnic motor fuel is obtained, and the less desirablehydrocarbons are readily separated and recovered in a form suitable forinclusion in ordinary fuels. Specific examples of such operations willbe presented below, and other similar applications and modificationswill be obvious to those skilled in the art. a

This invention is also applicable to mixtures of normally gaseoushydrocarbons, especially to mixtures containing normally gaseousolefins. A part of the products of cracking and reforming operationsconsist of normally gaseous hydrocarbons, both olefin and paraflin.Large amounts of normally gaseous paraifin hydrocarbons are present invarious places, and they may be subjected to thermal or catalytictreatment producing normally gaseous olefins. Although mixturesconsisting essentially of hydrocarbons oi the same number of carbonatoms per molecule, but containing both olefin and paraflinhydrocarbons, are readily formed by fractional distillation and thelike, it is not such an easy matter to separate these parafiins andolefins from each other. The application of my invention solves thisproblem nicely, as such fractions containing normally gaseous olefinsmay be readily extracted using SOz-olefin-resin oil as a selectivesolvent for the oleflns. The olefins may then subsequently be separatedin more concentrated form from the resin oil by distillation or thelike.

The resin oil brought into contact as a liquid with such gaseoushydrocarbon mixtures either in the gaseous state or the liquid statedissolves the unsaturated hydrocarbons more readily than the saturated,thereby effecting a concentration of the former relative to the latterin the resin oil, from which the unsaturated rich extract may berecovered, conveniently, by distillation.

It will be seen from this discussion that my invention is applicableover a wide range. Although the discussion has been limited to variousmore or less well defined fractions of hydrocarbon mixtures, myinvention is not to be c0nsidered to be limited thereto. Obviously, itmay be applied to narrow fractions of restricted boiling range and tocrude petroleum oils if other conditions warrant such treatment.

The following examples are set forth to illustrate specific applicationsof my invention only, and are not to be construed as limiting the samein any way, it being understood that the invention is capable ofapplication in many ways other than these set forth below.

EXAMPLE I A hydrocarbon lubricating oil fraction known as 240 neutraloil and having the characteristics listed in Table II, was intimatelymixed and agitated with an equal volume of an SOz-olefinresin oil whichhad been derived by treatment of an SOz-butene-Z resin with aqueoussodium hydroxide. The mixture was homogeneous at 225 F., but separatedinto two distinct layers at 220 F. After thorough settling at 210 F.,the resin oil was separated from the hydrocarbon layer. This layer, whenfreed of remaining resin oil by separation at a lower temperature andextraction with concentrated aqueous HCI, had the characteristics listedin Table II. A decided improvement in viscosity-temperaturecharacteristics, as exemplified by the increased V. I. (viscosity indexof Dean and Davis) and the decrease in the ratio of viscosity at F. andat 210 F. is clearly seen.

TABLE II res'in oil phases were as shown in Table V. The Solventextraction of lubricating oil portion of the hydrocarbon undissolvedcontained a reduced concentration of cyclohexane.

Original I Purified un- Properties 240 neutral dissolved TM? V IPreferential extraction of naphthenes 31890812 at: (Sayboit sec.) 38 Ylscosi y a V 1 f Viscosity at 210 F" 47 41 gggf g olumepf V. I 63 2 T mpatur hydrocarbon resin o1l Viscosity at 100 F./viscosity at 210 F 5. 34. 7 e, layer Percent Percent EXAMPLE II C As anexample of theapplication'of my invenggg tion to the separation of hydrocarbons in therange of present day motor fuels, the following data are to beconsidered. An artificial blend of octane and benzene was prepared, withthe composition as given in Table III. Of this blend, 40 volumes wereagitated with 30 volumes of an .SOz-olefin-resin oil at C. The portionof hydrocarbon undissolved by the resin oil had the composition given inTable III after being distilled from the traces of SOz-olefin-resin oilwhich it contained. p

The extract consisted of benzene with a rela tively small'amount ofoctane.

TABLE III As a further example of the application of my invention to theseparation of hydrocarbons in the gasoline range, the following data arepresented. An artificialblend of octane and diiso-' butylene, an octane,was prepared, the composition being as given in Table IV. or this blend,'78 volumes were extracted with 90 volumes of an SOz-olefin-resin oil.

. TABLE IV I Preferential extraction of olefins Composition CompositionConstituent of ori inal of undissclved mixture hydrocarbons I PercentPercent Octane r Octene -4 49 v EXAMPLE I? A blend of 50 per. centcyclohexane and 50 per cent octane was prepared-and intimately contactedwith an equal volume of an SOz-oleflnresin oil at various temperatures.The relative volumes of the undissolved hydrocarbon and EXAMPLE V As anexample of the application of my invention to normally gaseoushydrocarbons, a refinery butane-butene fraction maintained in the liquidstate may be passed in countercurrent contact to a stream ofSOz-olefin-resin oil in an absorption tower, the resin oil entering atthe top and the butane-butene fraction at the bottom, in conventionalabsorber manner. The unabsorbed hydrocarbons passing from the top of theabsorber are substantially depleted in olefin content, and olefins arerecovered from the resin oil passing from the absorber at the bottom.These olefins may then be subjected to polymerization or similarprocesses.

This process may be carried out with the hydrocarbonsin either a gaseousor liquid phase. Liquid phase operation isoften quite advantageous,smaller apparatus then being required. In any process in which anSO2-olefin-resin oilis used as a selective solvent, the optimumconditions of temperature, pressure, relative concentrations of resinoil and materialbeing subjected to extraction, and the number of stagesof extraction will be variable and dependent to a great extent upon' thecomposition of the material to be extracted and'upon the degree ofextraction desired. For anygiven material the optimum conditions ofthese variables may be easily determined by trial and experiment by oneskilled in the art.

As indicated in Example I, the SOi-oleflnresin oil is soluble in aconcentrated aqueous solution of hydrogen chloride. I have found thatthe solubility of the resin oil is not confined to concentratedsolutions of hydrogen chloride, but that I solutions of nitric acid,sulphuric acid and the like also display this phenomenon. I have alsofound that solutions of SOz-olefin-resin oil in concentrated aqueoushydrogen chloride are miscible at room temperature but when heated orcooled there is separation into two phases. At

' ordinarytemperatures, SOz-olefin-resin oils are also miscible to agreater or less degree in the following organic solvents:

Methyl alcohol Nitrobenzene Ethyl alcohol Ethyl acetate Ether 1-4dioxane Acetone Nitromethane Carbontetrachloride Isoamyl sulphonechloroform, Neats-ioot oil Carbon disulphide I Castor oil I The use ofone or more of these solvents, either alone, or in combination with eachother or with resin oils from hydrocarbons, will often be of advantagein a solvent extraction process. Wa-

- solvents of less solubility for hydrocarbons, such as traces of water,in extracting the SOz-oleilm ter for example, can be incorporated in theresin oil to raise the temperature level above which completemiscibility with ,a hydrocarbon liquid undergoing extraction treatmentoccurs, and other liquids of lower miscibility with hydrocarbons thanthe resin oil itself may be so used.

I have also found that the SOa-olefin-resin oil as initially preparedfrom the reaction of the SOz-olefin-resin or complex with an alkali maybe resolved by treatment with hydrochloric acid solutions into twocomponents. These two components have essentially the same boilingpoints, but at ordinary temperatures one is liquid and the other is acrystalline solid. For instance, the oil from an SOzbutene-2-resin wascompletely dissolved in concentrated hydrochloric acid. This was dilutedwith about 7 volumes of water, and a crystalline material separated,while from the remaining solution a normally liquid product wasseparated by extraction with ordinary ether. The boiling points were asfollows:

Oily portion Because of the similarity in many properties, I do not wishto distinguish in the solvent extraction of hydrocarbons between theneutral oil as derived from an SOz-olefln-resin by treatment of theresin with alkali as described, and the neutral oil from which thecrystalline material has been separated. Therefore, when I speak ofSO2-olefinresin oils, it is to be understood that I may mean either ofthese materials. The crystalline material itself may be so used, attemperatures where the liquid state prevails and/or in the presence ofother solvents such as those disclosed which depress the solidifyingtemperature.

I claim: I

1. In a process for concentrating olefin hydrocarbons from'a mixture ofolefin and paraffin hydrocarbons by treatment with a selective solvent,the steps which comprise contacting said mixture with anolefin-SOz-resin oil thereby concentrating said olefins in said 011,separating the resin oil from the mixture, and removing the olefinconcentrate from the resin oil.

2. In the preparation of a relatively nonknocking motor fuel from anoriginal motor fuel of relatively greater knocking tendency andcontaining paraffln hydrocarbons and at least one other type ofhydrocarbons, the steps which comprise subjecting said original motorfuel to treatment with. an SOa-olefin-resin oil, and subsequentlyseparating from said soz-olefin resin oil a relatively non-knockingmotor fuel.

3. In the treatment of a hydrocarbon lubricating oil to improve itsviscosity-temperature characteristics, the steps which compriseintimately contacting said lubricating oil with an SO2- olefin-resinoil, a portion of said lubricating oil being substantially insoluble insaid SOz-olefinresin oil, and subsequently separating said insolubleportion as a lubricating oil. I

4. In the separation of olefin hydrocarbons from a mixture containingolefin and paraffin hydrocarbons, the steps which comprise contactingsaid mixture with a liquid comprising an SOz-oleiin-resin oil at atemperature at which there is a liquid phase comprised of said SO2-olefin-resin oil and olefin hydrocarbons and at least one other phase,isolating said liquid phase comprised of SOz-olefln-resin oil and olefinhydrocarbons, and separating from said liquid phase a hydrocarbonmixture containing olefin hydrocarbons in greater proportion than insaid mixture containing olefin and paraflin hydrocarbons.

5. In the separation of olefin hydrocarbons from a mixture containingolefin and paraflin hydrocarbons, the process which comprises contactingamixture containing paramn hydrocarbons and normally gaseous olefinhydrocarbons with a liquid comprising an SOz-olefln-resin oil underconditions of temperature and pressure such that there is a liquid phasecomprised of said SOz-olefin-resin oil and normally gaseous olefinhydrocarbons and at least one other phase, isolating said liquid phasecomprised of SOz-olefin-resin oil and normally gaseous olefinhydrocarbons and separating therefrom a hydrocarbon mixture containingnormally gaseous olefin hydrocarbons.

6. A process for improving a hydrocarbon lubricating oil which containsundesirable constituents, which comprises contacting said lubricatingoil with an olefin-SOz-resin oil to selectively dissolve the undesirableconstituents, and separating the resin oil from the remaininglubricating oil.

'7. A process for separating a concentrate of one type of hydrocarbonsfrom a hydrocarbon mixture of different types of hydrocarbons. at

least one of which is more hydrogen-deficient than the others, whichcomprises contacting said mixture with an SOz-olefin-resin oil therebyforming a concentrate of said more hydrogendeficient hydrocarbons insolution in said SO:- olefin-resin oil, separating said SOz-olefin-resinoil from said mixture and separating said concentrate from saidSOz-olefin-resin oil.

8. In a process for concentrating hydrocarbons of one homologous seriesfrom a mixture of hydrocarbons of at least two homologous series one ofwhich is hydrogen-deficient as compared with the other, the steps whichcomprise contacting said mixture with a selective solvent comprising anSOz-olefin-resin oil thereby concentrating hydrocarbons of saidhydrogen-deficient series in said solvent and separating said solventfrom said mixture.

9. In a process of separating a mixture of different types ofhydrocarbons, at least one of which is hydrogen-deficient as comparedwith another,.into at least two fractions having different composition,the step which comprises extracting said mixture with a liquid solventcomprising an organic compound containing sulfur and oxygen, andproduced by treating an SO2-olefin resin with an alkaline chemicalagent, whereby hydrogen-deficient hydrocarbons are extracted.

10. The process of claim 9 wherein said SO:- olefin-resin was formedfrom S02 and a 2-olefin.

11. In the process of separating hydrogendeficient hydrocarbons from ahydrocarbon mixture containing at least two types of hydrocarbons, oneof which is more hydrogen-deficient than the other, by extraction with aselective solvent, the improvement which comprises subjecting such ahydrocarbon mixture to an extraction with an SOz-olefin-resin 'oil underconditions to form an extract phase containing a substantial amount ofthe more hydrogen-deflm cient hydrocarbon, and at least one other phase,and "separating said phases.

12. In the preparation of a motor fuel containing substantially onlyparaflin hydrocarbons 5 from an original motor fuel'which contains par--drocarbons, the steps which comprise subjecting said original motor fuelto-treatment with an S0z-olefln-resin oil whereby hydrogen-deficienthydrocarbons are selectively dissolved, and subsequently separatingundissolved hydrocarbons.

ROBERT D. SNOW.

